4 results about "P-chloronitrobenzene" patented technology

The invention relates to the technical field of 4, 4 '-diaminodiphenylamine, in particular to a synthesis process of 4, 4'-diaminodiphenylamine, which comprises the following steps: dissolving parachloronitrobenzene, paranitroaniline and alkali in an organic solvent, heating, stirring, pouring into ice water, filtering, washing and drying to obtain 4, 4 '-dinitrodiphenylamine; adding the mixture, a catalyst and an organic solvent into a high-pressure reaction kettle, introducing hydrogen after nitrogen replacement, heating and stirring, filtering the catalyst after the reaction is finished, and recovering and reusing the catalyst; according to the synthesis process of 4, 4 '-diaminodiphenylamine adopting the steps, the reaction process is shortened, the steps of separation and purification of intermediate products are reduced, the production efficiency is improved, the loss in the production process is reduced, and the product with high purity and high yield is obtained.

This invention relates to a method for synthesizing hydroquinone, a pharmaceutical and chemical intermediate. The invention comprises the following steps: (1) hydrolysis of p-chloronitrobenzene in an alkaline solution, adjusting the pH to 5-6 with acid to obtain p-nitrophenol; (2) reduction of p-nitrophenol and hydrogen under catalytic conditions to obtain p-aminophenol; (3) diazotization of a dilute acid solution of p-aminophenol with sodium nitrite; the reaction solution reacts with a dilute acid solution used for hydrolysis to obtain hydroquinone; after the reaction, solvent extraction is performed, followed by concentration, centrifugation, and drying. The reactions are carried out in a microreactor system. Compared with existing hydroquinone production processes, this invention uses continuous flow technology for continuous production, greatly improving production efficiency and saving production costs. It solves the problems of high levels of waste, low selectivity, and high purification costs associated with traditional batch processes. Furthermore, the continuous flow production process has a lower scale-up effect, easier process control, and is suitable for industrial production.

The present application relates to the technical fields of chemical synthesis, and discloses a kind of catalyst and preparation method and the continuous chlorination production process of 3,4-dichloronitrobenzene, wherein the continuous chlorination production process of 3,4-dichloronitrobenzene includes the following steps: (1) adding multi-stage channel supported metal chloride catalyst into primary chlorination tower, secondary chlorination tower and tertiary chlorination tower; (2) feeding p-chloronitrobenzene raw material into primary chlorination tower, secondary chlorination tower and tertiary chlorination tower in sequence and introducing chlorine gas for chlorination reaction, the generated hydrogen chloride gas and unreacted chlorine gas escape from the top of the tower, enter the tail gas main pipeline, and the reacted chlorination liquid is fed into primary deacidification kettle and secondary deacidification kettle in sequence for deacidification treatment; (3) the deacidified chlorination liquid is fed into light-removing tower to distill p-chloronitrobenzene for recycling, the tower kettle material is fed into heavy-removing tower for treatment, tar is recovered from the tower kettle, and 3,4-dichloronitrobenzene is obtained by crystallization and purification of the tower top material.

The present application relates to the technical fields of chemical synthesis, and discloses a kind of catalyst and preparation method and the process method of wastewater-free production 3,4-dichloronitrobenzene, wherein the process method of wastewater-free production 3,4-dichloronitrobenzene includes the following steps: (1) adding self-dehydration type solid acid catalyst to primary chlorination tower, secondary chlorination tower, tertiary chlorination tower;(2) the p-chloronitrobenzene raw material is sequentially transported to primary chlorination tower, secondary chlorination tower, tertiary chlorination tower and is introduced into chlorine gas to carry out chlorination reaction, the generated hydrogen chloride gas and unreacted chlorine gas escape from tower top, enter exhaust gas main pipeline, and the chlorinated liquid of reaction is sequentially transported to primary deacidification kettle and secondary deacidification kettle to carry out deacidification treatment;(3) hydrogen chloride gas and unreacted chlorine gas in exhaust gas main pipeline are discharged after treatment reaches standard;(4) deacidification chlorinated liquid is sequentially treated by light removal tower and heavy removal tower, crystallization purification, and 3,4-dichloronitrobenzene is obtained.